Many Republicans are hoping that the Supreme Court bars subsidies on federal health exchanges. But such a ruling could create a big headache for the GOP. WSJ’s Jerry Seib explains. Photo: AP

This transcript has been automatically generated and may not be 100% accurate.

... one of the biggest events of the year in Washington is going to be a ruling by the Supreme Court that could seriously undermine the Affordable Care Act otherwise known as Obamacare ... and you might think the Republicans because they hate Obamacare so much would be cheering for Supreme Court decision that does in fact undercut the law ... to Republicans in town now we're starting to worry that negative Supreme Court decision on the lot next to create some big problems for them as well ... here's what's going on there's a case before the Supreme Court that says it's illegal under the law ... for consumers to receive subsidies from the federal government ... if they bought their health insurance policies on the federal exchange that's because along the way it's written envisions state setting up their individual exchanges for people to buy insurance under Obamacare ... but in fact more than thirty states have not done that and so there that their citizens are buying insurance on a federal exchange this is a fluke in the way the law was written ... if the core rules against the the the the administration on this is spending millions of people will lose their subsidies ... but his Republicans are worried about at that point prison Obama is likely to turn the Congress and say I listen to someone wish to fix this flaw ... in in the act I expect you to move on its own an if if you go ... these millions of people who've lost their subsidies will be plenty knew the Republicans not ask ... the Obama administration ... has to put Republicans an awkward position because ... they don't really want to be in the business of fixing Obamacare but they also don't wanna take responsibility for people may maybe many people ... losing their health insurance coverage because of this court decision so ... both parties have a lot to lose depending on how the Supreme Court rules ... in that there will be a very tricky process of fitting out what to do